Methods HLA-A, B alleles polymorphism in 197 cases with ALL and 5841 normal umbilical cord blood controls were determined by PCR with sequence specific olignucleotide probe(PCR-SSO).

• 方法采用聚合酶链反应-序列特异性寡核苷酸探针(PCR-SSO)方法,对197例北方汉族儿童ALL患者和5841例健康脐带血样本HLA-A,B等位基因多态性进行研究。